javascript 公民身份號碼驗證代碼

function isidcardno(idvalue) {
        var len=0, re;
        len=idvalue.length;
        if (len == 15 && isnumberstring(idvalue,"1234567890"))
        re = new regexp(/^(d{6})()?(d{2})(d{2})(d{2})(d{3})$/);
        else if (len == 18 && isnumberstring(idvalue,"1234567890xx"))
        re = new regexp(/^(d{6})()?(d{4})(d{2})(d{2})(d{3})(d)$/);
        else {
       // alert("輸入的公民身份號碼不合法，請重新輸入!");
        return false;
        }
        var a = idvalue.match(re);
        if (a != null){
                if (len==15){
                    var d = new date("19"+a[3]+"/"+a[4]+"/"+a[5]);
            var b = d.getyear()==a[3]&&(d.getmonth()+1)==a[4]&&d.getdate()==a[5];
          }else{
                    var d = new date(a[3]+"/"+a[4]+"/"+a[5]);
            var b = d.getfullyear()==a[3]&&(d.getmonth()+1)==a[4]&&d.getdate()==a[5];
          }
          if (!b) {
      //alert("輸入的公民身份號碼 "+ a[0] +" 的日期不合法，請重新輸入!");
      //alert("輸入的公民身份號碼不合法，請重新輸入!");
      return false;
     }
        }
        if(len == 18 && !verifygmsfhlast(idvalue)){
      if (idvalue.substr(17,1)=='x'){
      //alert("公民身份號碼的最後一位校正碼不正確('x'應為大寫),請檢查!");
      }else
      {
      //alert("輸入的公民身份號碼不合法，請重新輸入!");
      }
            return false;
        }
        return true;
}

function verifygmsfhlast(sval){
        if(sval.length != 18) return false;
        var wi = new array(7,9,10,5,8,4,2,1,6,3,7,9,10,5,8,4,2,1);

        var vi = new array(1,0,'x',9,8,7,6,5,4,3,2)
        var ai = new array(17);
        var sum = 0;
        var remaining = 0;
        var verifynum = "";
        //通過迴圈把18位身份證的前17位存到數組ai中
        for(var i = 0; i < 17; i++){
            ai[i] = parseint(sval.substring(i,i+1));
        }
        for(var m = 0; m < ai.length; m++){
            //加權
            sum = sum + wi[m] * ai[m];
        }
        remaining = sum % 11;
        if(remaining == 2){
            verifynum = "x";
        }else{
            verifynum = vi[remaining];
        }
        if(verifynum != sval.substring(17,18)){
            return false;
        }else{
            return true;
        }
    }